Storing silicone molds with desiccant?

Discussion in 'Replica Props' started by msleeper, Jul 23, 2015.

  1. msleeper

    msleeper Sr Member

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    I've got a question for anyone whose workshop gets super humid like the space where I work at.

    Would it be harmful to keep my molds stored with silica desiccant? I'm keeping them in ziplock bags to keep ambient dust off of them, and with the rain and general humidity here in Georgia, I want to protect them as best I can. The workshop at the space I'm a member of is basically a warehouse, so it's super hot and humid in the summer. It's probably over kill, but I have a ton of desiccant for storing 3D printer filament.

    If it matters, most of them are tin-cure (Mold Max specifically).
  2. robn1

    robn1 Master Member

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    I was waiting for replies from someone who knows, but since none have come forward I'll mention my uninformed concern: desiccant may dry out the oils in the silicone. I don't know if this is the case but I'd at least test it first.
  3. metamorphicsfx

    metamorphicsfx New Member

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    All of my molds are silicone with either fiberglass or MDF casings, I've stored my mold in the attic for the past 14 years, -30f to 40f. Moisture has never been an issue, as long as you make sure the mold is dry before you cast your urethane, which can be moisture sensitive, there should be no problem. If your casings are made of plaster moisture might be a problem with mildew, but the silicone will never be affected.

    I agree that putting the silica directly on the silicone could rob it of its oils.
  4. TazMan2000

    TazMan2000 Sr Member

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    The oils will leach out over time anyway, but using desicant may speed up the process and prematurely age your molds. A zip lock back or a plastic icecream pail will do well. I would think that storing molds at room temperature would probably be the be the best for them. Leaving them in the garage or attic where they might experence extremes in temperature probably won't be good for them, either.

    Just my two cents.

  5. msleeper

    msleeper Sr Member

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    Thanks guys. I'll stick to keeping them in ziplock bags. I might do a test the next time I'm pouring silicone, make a small throwaway mold of something and stick it with some desiccant and see how it acts long term. Science!

    Right. Long term, they do wind up in a temperature controlled storage unit. The ones I'm working with right now I am casting out of on a fairly regular basis so I'm keeping at the workshop, and as a result they're sitting in the hot and humid environment in between casting days. I do keep my unused silicones and resins in the temperature controlled chemistry lab, since I know from experience heat/humidity can kill unused resin.

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